Review: Audeze Sine On-Ear Headphone

There is turmoil in the world of headphones. As rumors swell that Apple will be removing the 3.5mm analog headphone jack from its next version of the iPhone, many are worried that they will be forced to carry extra dongles or choose between a limited set of headphones that are “iPhone compatible.” Others argue that the 3.5mm jack is old tech overdue for replacement, and Apple is the best company to do it. One thing is for sure – if the switch to Lightning for audio is to succeed, we want some proof that it will be worth the hassle. With the Sine ($449 – $499) and its Cipher Lightning cable, Audeze has given us a peek into the future of iPhone listening.

Though not quite a household name, Audeze is well known by audiophiles as a manufacturer of high end planar magnetic headphones. Planars differ from the more traditional dynamic driver design in that they don’t use a circular cone and voice coil. Instead, they use a thin diaphragm laced with conductive traces between arrays of strong magnets. As electricity is sent through the traces on the diaphragm, it interacts with the magnetic field and vibrates, generating sound. Planars are known for their excellent detail and tight, deep bass, but were (until recently) not seen in the portable headphone market due to their greater weight and tendency to be power hungry. Audeze’s Sine is one of the first planar magnetic headphones designed to be portable, and is the first available in an on-ear form factor.

Out of the box, the Sine just screams “premium.” Nearly every surface is made of metal or covered in leather. Though we usually favor utilitarian design in a headphone, the Sine’s luxury flourishes are tasteful and understated. The rounded-triangle ear cups swivel and can be laid flat, with ear pads that are fairly large for an on-ear headphone. At .77 pounds (with cable), the Sine is heavy for an on-ear portable, but svelte for a planar magnetic. Included in the box is a suede carrying case, 6.3mm plug adapter, analog cable and, if you bought the $499 version, a Cipher Lightning cable. At this price point, we would have liked to have seen a hard carrying case included as well.

The Sine is one of the most comfortable on-ear headphones we have yet tested. The headband has a smooth, silent sizing mechanism and just enough padding that weight never becomes an issue. The Sine’s ear pads are thin, but soft and just loose enough to maintain seal as your head moves. The Sine’s cables are less accommodating — their stiff, flat rubber construction resists tangles, but also gives them a mind of their own when connected to your phone or in storage. The Sine’s build quality is top notch, with tight seams, perfect metal-to-leather transitions, and no exposed screws. We experienced occasional squeaks from the Sine’s moving parts, but no more often than to remind us that even the joints are all metal — even the unwanted sounds from the Sine are “premium.”

Most of our complaints with regard to comfort are standard fare for on-ear headphones. Our ears became warm during long listening sessions, and we experienced discomfort when using the Sine while wearing glasses. However, we did experience an issue unique to the Sine – its ear pads have a tendency to seal too well. We found the Sine’s tight seal to be great for bass and isolation in noisy environments, but at times the Sine can give the sensation that it is trapping too much air in front of the driver. This can cause a feeling of pressure and dull the sound, almost like pressing a palm up against the ear. This problem is easily solved by a small readjustment to relieve the pressure, but it happened often enough to be annoying.

We began our tests of the Sine with the analog cable and were immediately impressed. Though we had to crank the volume up on the iPhone to achieve reasonable listening levels, we found the Sine to have a balanced and pleasing sound with that was enjoyable with nearly every genre of music we tested. We found the Sine to have a slightly relaxed tone, which made some guitar rock sound somewhat blunt and less detailed than other genres. Even so, we had several lean-forward moments when details and dynamics were revealed in songs that we hadn’t heard before.

While the Sine sounds good directly out of the iPhone, the low power output of the iPhone’s internal amplifier simply can’t drive them to their full potential. Even though the Sine has a very low impedance (only 20ohm), their planar magnetic drivers will happily accept as much power as you’re willing to give them. We tested the Sine with an iPhone, a portable amplifier, and even the very powerful Schiit Lyr 2 amplifier on high gain — the Sine’s sound only improved as we added power. Still, the Sine is intended to be a portable headphone; that’s where the Cipher Lightning cable comes in.

The Cipher cable looks nearly identical to the analog cable except for its Lightning connector termination and a plastic control pod located at the center of the cable. The pod has an understated design, and is narrow and light despite housing a DAC, amplifier, and other electronics. The front of the pod features familiar three-button iOS controls, and a microphone is mounted on the rear. The Cipher cable works as it should on the current version of iOS (9.3), but is not listed in the output selector menu and was occasionally not recognized when plugged in. If Apple is planning on making Lightning cables the standard for future generations of the iPhone, we expect iOS 10 to bring integration improvements.

Audeze lists the “optimal power requirement” for the Sine at 500mW to 1W, which is far more than the iPhone’s internal amplifier was designed to produce. It appears that the Cipher cable is able to draw extra power from the Lightning connector, because the Sine is both louder and more dynamic using the Cipher cable. Where we had to keep the iPhone’s volume at around 80 percent for acceptable volume using the analog cable, the Cipher cable produced about the same volume at 50 percent. This extra power draw had an impact on battery life, but not enough to be a problem even for the two-year-old battery in our iPhone 6 Plus.

The extra power provided by the Cipher cable doesn’t only make the Sine louder; it makes the Sine sound better. With the Cipher cable, the same tracks were presented with a significant improvement in dynamics and detail, especially with the guitar tracks that had sounded underwhelming from the standard headphone jack. Drums were punchier, imaging was better, and the Sine’s bass seemed to extend even lower. We noticed an overall warmer sound when we used the Cipher cable, though we can’t say whether this was attributable to the power boost or a trick of tuning the cable’s amp. This overall improvement in sound is complemented by Audeze’s free app, which offers a 10-band equalizer and the ability to save settings in the cable’s internal memory.

The Sine and Cipher cable make a great case for Lightning audio from iOS devices, but our time with the Sine brought some new concerns to light. Some manufacturers of Android phones have already deleted the 3.5mm jack in favor of a different standard – USB-C – which means Sine will be an Apple-only headphone. Even those who fully embrace the Lightning connector and Apple’s ecosystem have limited options – not even Apple includes the Lightning connector on anything other than its portable devices. This problem, combined with the fact that there is currently no way to charge the iPhone while using a Lightning headphone cable, essentially forces users to carry a second, non-Lightning cable on any trip longer than a few hours. None of these issues are Audeze’s fault, but they create a slight cause for concern — at least until we wait for Apple to make its next product announcements.

The Audeze Sine is a well-built, luxurious headphone that exhibits a tremendous amount of technical competence. With the “iPhone 7” on the horizon, the Sine makes an excellent case for adding new technology to headphone cables. Not only can headphone manufacturers choose audio hardware that complements their headphones, they can also create apps for a unique integration between hardware and software. Though there are clearly problems to be solved, Audeze’s Cipher Lightning cable makes it possible to feed power hungry planar magnetic headphones without an external amp. Whatever the fate of the headphone jack turns out to be, we think the Audeze Sine with Cipher Lightning cable is worthy of our strong general recommendation.